W&M ScholarWorks VIMS Articles Virginia Institute of Marine Science 1997 Larvae of Gillellus jacksoni, G-uranidea (Dactyloscopidae), Stathmonotus stahli tekla, and S-hemphilli (Chaenopsidae), with comments on the use of early life history characters for elucidating relationships within the Blennioidei MR Cavalluzzi Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/vimsarticles Part of the Aquaculture and Fisheries Commons Recommended Citation Cavalluzzi, MR, Larvae of Gillellus jacksoni, G-uranidea (Dactyloscopidae), Stathmonotus stahli tekla, and S-hemphilli (Chaenopsidae), with comments on the use of early life history characters for elucidating relationships within the Blennioidei (1997). Bulletin of Marine Science, 60(1), 139-151. https://scholarworks.wm.edu/vimsarticles/1539 This Article is brought to you for free and open access by the Virginia Institute of Marine Science at W&M ScholarWorks. It has been accepted for inclusion in VIMS Articles by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. BULLETIN OF MARINE SCIENCE. 60(1): 139-151. 1997 LARVAE OF GILLELLUS JACKSONI, G. URANIDEA (DACTYLOSCOPIDAE), STATHMONOTUS STAHLI TEKIA, AND S. HEMPHILLI (CHAENOPSIDAE), WITH COMMENTS ON THE USE OF EARLY LIFE HISTORY CHARACTERS FOR ELUCIDATING RELATIONSHIPS WITHIN THE BLENNIOIDEI Martin R. Cavalluzzi ABSTRACT Larvae of the families Dactyloscopidae (Gillellus jacksoni, G. uranidea) and Chaenopsidae (Stathmonotus stahli tek/a, S. hemphilli) are described from specimens collected in Ambergris Cay, Belize. Larvae are characterized by precocious development of fins and sensory canals, and little pigmentation overall, with the majority of pigmentation occurring ventrally. Pigment distributions in larvae are summarized for the six blennioid families. There are no unifying pigment characters among blennioid larvae. Larvae possess the six shared specialized char- acters or character complexes (as described in adults) currently used to hypothesize the mono- phyly of the Blennioidei, and thus, provide no new phylogenetic information. The suborder Blennioidei comprises six families: Blenniidae, Chaenopsidae, Clinidae, Dactyloscopidae, Labrisomidae, and Tripterygiidae (Springer and Frei- hofer, 1976; George and Springer, 1980; Springer, 1993). There are 127 genera and 732 species recognized (Nelson, 1994) for which early life history informa- tion is known for approximately 38 genera and 55 species. Within the tropical and subtropical western North Atlantic, early life history information is available for only five species ofblenniids (Chasmodes bosquianus, C. saburrae, Hypsoblennius hentz, Hypleurochilus geminatus, and Ophioblennius at/anticus macclurei), and one species of labrisomid (Paraclinus marmoratus) (Hildebrand and Cable, 1938; Breder, 1939, 1941; Fritzsche, 1978; Peters, 1981; Fahay, 1983; Labelle and Nursall, 1985). Larvae of the other families are un- known (Richards, 1990). Herein, I describe four blennioid species, summarize salient pigment characters for the six blennioid families, and discuss the use of ontogeny for elucidating relationships within the suborder. The descriptions of Gillellus spp. represent the first descriptions of dactyloscopid larvae. METHODS Larvae were captured near Ambergris Cay (18°N, 88°W), Belize, Central America (Maddox. 1992). Specimens were collected with a bridled 1-m ring fitted with a 333-f.Lmmesh N1TEX plankton net. The net was towed at the surface immediately after dusk for 10 min by a small boat at a speed of approximately 1 knot. Specimens were fixed in a seawater buffered formalin (5%) solution, and preserved in 70% ethyl alcohol. Larvae were separated into morphotypes based on pigment characters, and representatives of each morphotype were cleared and stained following procedures outlined in Potthoff (1984) to facilitate meristic counts. Larvae were identified by comparing counts with published meristic data (Bohlke, 1968; Dawson, 1982; Greenfield and Johnson, 1981; Hastings and Springer, 1994; Springer, 1955). Illustrations were made with the aid of a camera lucida mounted on a WILD M5 stereoscope. Nomenclature regarding sensory pore and canal systems is that of Johnson and Greenfield (1976). Principle caudal-fin rays are defined as those that are supported by the hypural plates. Measurements and descriptions of body shape (e.g., elongate, moderate, deep), head size, and eye size are as defined by Leis and Tmski (1989). Meristic and morphometric data are presented in Tables 1 and 2, respec- tively. Material examined is listed by institutional abbreviation (Leviton et aI., 1985), catalog number, 139 140 BULLETIN OF MARINE SCIENCE, VOL. 60, NO. I, 1997 Table I. Sizes (mm SL) and meristic data of Gillellus jacksoni, G. uranidea. Stathmonotus hemphilli and S. stahli tekla larvae captured in Belize, Central America. Data are derived from examination of cleared and stained specimens. ND = no data. Caudal fin Body Dorsal Anal PeclOral Pelvic Pro- Taxon length fin fin fin fin Principle current Vertebrae Dactyloscoidae Gillellus jacksoni 7.7 1ll+XIV,20 Il,28 12 1,3 5+5 4+3 10+30 7.9 1ll+XVI,19 11,29 12 1,3 5+5 3+3 11+31 8.2 1ll+XV,18 11,28 12 1,3 6+5 4+3 10+31 8.4 1ll+XVI,18 11,28 12 1,3 5+5 4+3 11+30 Gillellus uranidea 6.7 m+X,16 11,22 13 1,3 6+6 2+1 10+24 7.3 XV,15* 11,22 13 1,3 5+5 2+2 10+25 7.9 m+XI,16 11,21 \3 1,3 6+5 3+2 10+24 8.3 m+XII,15 11,22 13 1,3 5+5 3+2 10+24 8.4 III+ XI, 16 n,22 13 1,3 5+5 3+3 10+25 Chaenopsidae Stathmonotus hemphilli 7.8 L,O 11,26 5 1,2 5+5 1+1 24+32 6,2 48t 26t 0 0 6+6 1+1 23+3\:1: Stathmonotus 7.5 XLI,O 11,23 8 1,2 6+5 2+1 17+28 .Hahli tekla 7.5 XL,O 11,23 ND 1,2 6+6 2+1 17+28 7.6 XLI,O 11,24 ND 1,2 6+6 2+2 17+28 8.4 XLI,O 11,23 9 1,2 6+6 2+2 17+28 •••The 4 anterior-most dorsal-tin spines are 'Variously separated from one another and the rest of the fin, but there is no distinct three- spined dorslll finlet. t The total number of pterygiophores presumably supporting spines in dorsal fin and spines and segmented rays in anal fin. t The penultimate and antepenultimate vert{:bral centra are fused (2 neural spines. 2 haemal spines): the actual number of vertebrae could be interpreted as 23 +32. number of specimens examined, size range, location of capture, state of material examined (i.e., cleared and stained, radiograph, whole; left blank if whole), and date of collection. Gillellus jacksoni (Dactyloscopidae) Figure 1 Material Examined.-Larvae: VIMS 9508, 11, 6.7-8.4 mm SL (4 specimens, 7.7, 7.9, 8.2, 8.4 mm SL, cleared and stained), 13 August 1985. Adults: ANSP 144081, 1, 24.9 mm SL, holotype, Lesser Antilles, St. Barthelemy, radiograph; ANSP 105438,4,20.1-24.1 mm SL, paratypes, taken with holotype, radiograph; ANSP 116536, 1, 14.8 mm SL, paratype, Lesser Antilles, An.guilla Island, radiograph; ANSP 116535, 1, 16,9 mm SL, paratype, Grenadine Island, radiograph. General Morphology.-Larvae elongate, slightly laterally compressed, with short gut. Head moderately large with short snout. Maxilla terminates below midpoint of pupil. Lower jaw projects beyond upper jaw. Opercles partially crenulate, ex- tend ventrally beyond body, overlap below isthmus, lack fimbriae on dorsopos- terior margin, Eyes lateral, as opposed to superior in adults, Four to eight teeth on each dentary, five or six teeth on each premaxilla, upper and lower pharyn- gobranchial tooth patches present, in larvae of 7,7-8.4 nun SL. No gas bladder. Full complement of fin rays present by 6.7 mm SL. Anlage of a genital papilla originating on posterior rim of anus. Sensory pores include infraorbital, preoper- cular, and mandibular series. Pigment.- "Y" -shaped melanophores (24-28 total) at bases of anal-fin soft rays; number and position variable, ranging from one immediately posterior to base of each soft ray to melanophores absent from one to four soft rays, with the ante- riormost soft ray typically lacking a melanophore. Two to four stellate melano- CAVALLUZZI: DACfYLOSCOPID AND CHAENOPSID LARVAE 141 M ",. Mt'- N N Cji~o Cji;:;;8 -o Cji;::!;O- s:;00 ;:::00 si;:: 0 0 o o 00 a-, -d\Q~ 1-0 ;::!;OO o '.0'.0 00 o 0lf"l0 .,.) 100 02;00 00 t'- M ci~- IMO ~OO o *If"l N 0""- 1 "!~ ~OO o M",. O-('>.l l"l~ ~OO o 142 BULLETIN OF MARINE SCIENCE, VOL. 60, NO. I, 1997 A Figure L Postfiexion larva of Gillellus jacksoni (Dactyloscopidae) (VIMS 9508, 7,6 mm SL). A) lateral view, scale = 1 mm; B) ventral view of head and pelvic region, scale = 0.5 mm. phores on abdomen and one at cleithral symphysis. One 6.9 mm SL specimen with ventral midline melanophore on caudal peduncle. Internal pigment in ventroanterior, dorsoanterior, and dorsoposterior patches on gut. One internal stellate melanophore in dorsoposterior area of parasphenoid. Comments.-Gillellus jacksoni has been reported only from the vicinity of the Lesser Antilles (Dawson, 1982); its collection in Belize represents a significant range extension (-1900 km). All larvae were collected in August over rocky substrate containing corals and sponges. Gillellus uranidea (Dactyloscopidae) Figure 2 Material examined.-Larvae: VIMS 9509, 12, 3.6 mm NL-8.4 mm SL, (5 specimens, 6.7, 7.3, 7.9, 8.3, 8.4 mm SL, cleared and stained), 13 August 1985. Adults: USNM 276136, 1, 18.5 mm SL, cleared and stained, Carrie Bow Cay, Belize; USNM 270071, 1,25.6 mm SL, radiograph, Belize; USNM 276136, 1,21.0 mm SL, radiograph, Carrie Bow Cay, Belize; USNM 261340, 2, 22.9 and 24.0 mm SL, radiograph, Looe Key, Florida.